Trimethylsilyl propargyl

To make tryptophan analogs, Gronowitz and coworkers conducted a pyrrole annulation from an aminoiodopyrimidine utilizing the Larock indole synthesis conditions (see Section 1.10.) [80]. They prepared heterocondensed pyrrole 115 by treating 4-amino-5-iodopyrimidine 114 with trimethylsilyl propargyl alcohol under the influence of a palladium catalyst The regiochemical outcome was governed by steric effects. 

Chemla, F. Bernard, N. Normant, J.-F. Meta-lation of 3-trimethylsilyl propargyl chloride a stereoselective access to troras-propargylic oxi-ranes. Tetrahedron Lett. 1999, 40, 75-78. 

Hydromagnesiation butenolides.1 Reaction of optically pure y-trimethylsilyl propargylic alcohols with isobutylmagnesium bromide catalyzed by Cp2TiCl2 (14,... 

Although not described as such, this reactivity of silver as a Lewis acid in C-C bond formation via enamines was already known and actually described in the synthesis of complex indole alkaloids. A A-sulfonyldienamine embedded within a polycyclic indole ring system added to the trimethylsilylated propargyl arm of this system, leading in high yield to a new six-membered ring (Scheme 10.71).110... 

Scheme 8 2,3-rearrangment of steroial 17-ethylidene 16-trimethylsilyl-propargyl ethers... 

Scheme 13 shows additional examples of constructions of four-carbon chains functionalized appropriately for condensation to pyrroles. Af,Af-bis(trimethylsilyl)propargyl amines can be converted to ketones or esters by lithiation and acylation. These compounds then undergo cuprate addition. The resulting allenyl silyl ethers cyclize to pyrroles on treatment with acid <93T4603). 

CP2C0 catalyses the condensation of acetylene and mono-substituted acetylenes (but not di-substituted acetylenes) with nitriles at 150° to give 30-70% yields of substituted pyridines [WakatsuM Yamazaki Synthesis 26 1976], This synthesis has been applied successfully in a 2+2+2 cycloaddition reaction between di(trimethylsilyl)propargyl ether and acetonitrile to prepare a pyridine intermediate whieh was used to obtain pyridoxine (vitamin Be) [Greiger et al. Helv Chim Acta 67 1274 1984. ... 

In the following step, the trimethylsilyl propargyl units are deprotected. In a 50 ml round flask, the protected polymer PI (0.401 g, 2.045 mmol) is dissolved in THE (20 ml) and the solution is cooled down with an ice bath. Next, 2.7 ml (2.7 mmol) of a 1 M THE solution of tetrabutylammonium fluoride (TBAE) are added dropwise via a syringe. After 10 min, the ice bath is removed and the solution is stirred further 1.5 h. Subsequently, the product is precipitated in a methanol/water... 

Form Supplied in colorless liquid not commercially available. Analysis of Reagent Purity IR (tf) 2955,2900,1935,1250,1210, 1055,840,800,750, and 690 cm H NMR (60 MHz, CDCI3) 50.15 (s, 9H),4.27 (d, 2H, /= 7.7),4.88 (dd, IH,7= 6.6,7.7). Preparative Method two methods have been reported for the preparation of (trimethylsilyl)allene [(TMS)allene] (1). Reductive deoxygenation of the tosylhydrazone derivative affords the title compound in 51% yield. The tosylhydrazone is readily prepared from the corresponding aldehyde, which in turn is accessed by formylation of (trimethylsilyl)ethynylmagnesium bromide with DMF (eq 1). (TMS)allene has also been prepared by flash vacuum pyrolysis of methyl (trimethylsilyl)-propargyl ether, which is obtained from silylation of methyl propargyl ether (eq 2)7... 

In another recent study on the synthesis of saniconductor polymers by a combination of CRP methods, Lang et al. [161] reported the use of H NMR and SEC to monitor the kinetics of NMP of trimethylsilyl propargyl acrylate and investigating side reactions leading to increase in polydis-persity. Subsequent click reactions with an azide functionalized perylene bisimide derivative overcome these limitations, as proven by H NMR and FTIR analysis. 

Brown, H. C. Khire, U. R. Narla, G. 1995. B-(Y-(trimethylsilyl)propargyl)diisopino-campheylborane A new, highly efficient reagent for the enantioselective propargylboration of aldehydes. Synthesis of trknethylsilyl-substituted and parent a-allenic alcohols in high optical purity. J. Org. Chem. 60 8130-8131. 

Wittig rearrangement of acetals has been probed.However, the reaction of benzyl Y-(trimethylsilyl)propargyl ether with Bu"Li has been shown to yield the ortho-12,3 ]- rather than the [1,2]-Wittig product. The enantioseleetive... 

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